Re: [linux-pm] runtime PM usage_count during driver_probe_device()?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi,

On Fri, Jul 1, 2011 at 8:33 AM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:

> In theory it is possible that a subsystem (e.g. bus type) will enable
> runtime PM for devices without drivers and will (for example) put them
> into low power states until the drivers are loaded.  Then, it makes
> sense for the core to prevent such transitions from racing with .probe().
>
> I'm not sure if this happens in practice, though, but also I'm not sure
> whether or not that's used by USB.  Moreover, even if that doesn't happen
> right now, it may start to happen at one point.

It should be used by USB, for example, uvcvideo driver has enabled
auto suspend already:

    - rmmod uvcvideo

    - usb video class device auto suspended

    - modprobe uvcvideo       #driver_probe_device()


thanks,
-- 
Ming Lei
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Arm (vger)]     [ARM Kernel]     [ARM MSM]     [Linux Tegra]     [Linux WPAN Networking]     [Linux Wireless Networking]     [Maemo Users]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Trails]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux